Surgical tool system with a handpiece having a valve assembly for regulating the fluid pump connected to the handpiece

ABSTRACT

A surgical tool system with a handpiece that is directed towards a surgical site. Irrigating fluid from a pump is pumped through a conduit integral with the handpiece for application to the surgical site. A valve regulates fluid flow through the handpiece conduit. A valve state sensor monitors the position of the valve and generates a sensor signal representative of valve state. The sensor signal is applied to a control unit that regulates actuation of the pump. The control unit regulates the actuation of the pump based on the valve state as indicated by the sensor signal. The pump may be a variable flow rate pump; the control unit increases pump output when the sensor signal indicates the valve is in fully opened position. The handpiece may include a suction fitting; the valve can selectively connect the conduit to the pump or the suction fitting.

[0001] This application is a divisional of U.S. patent application Ser.No. 09/302,148, filed Apr. 29, 1999, now U.S. Pat. No. ______, thecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] This application relates generally to powered surgical handpiecessuch as those employed in endoscopic surgery. More particularly, thisinvention is directed to a powered surgical handpiece that includes anirrigator for applying fluid to a surgical site, a suction conduit fordrawing fluid from the site, a means for clearing the suction conduitand a motor for actuating a complementary cutting accessory.

BACKGROUND OF THE INVENTION

[0003] The powered handpiece has evolved into an important tool forperforming surgical procedures. A typical powered handpiece includes ahousing that contains an electrically driven motor. A coupling assemblyis attached to one end of the handpiece. The coupling assembly is usedto releasably secure a cutting accessory to the motor so that the motor,when energized, actuates the cutting attachment. The development ofpowered surgical handpieces and their complementary cutting accessorieshas made it possible to cut, shape and remove both hard and soft bodytissue at faster rates and with a higher degree of accuracy than waspossible with the manually powered tools that preceded them.

[0004] When a cutting attachment is actuated, the cutting action causesloose tissue and other debris to develop at the surgical site. Thismaterial is removed by applying an irrigation fluid to the site and alsodrawing a suction from the site. The irrigation fluid serves as atransport media for carrying the debris; the suction draws away thefluid and the entrained debris. In order to perform this irrigation andsuction, some cutting attachments are provided with conduits throughwhich fluid is applied to and drawn from the surgical site. For example,cutting attachments designed to perform endoscopic surgery or sinussurgery often include a static outer sleeve in which a rotating tube isfitted. The head of the rotating tube is provided with some type ofcutting surface or cutting member. Each of these attachments is furthershaped so that irrigation fluid can flow to the surgical site throughthe annular channel between the rotating tube and the static sleeve. Theinner rotating tube is further provided with an opening adjacent thehead through which a suction is drawn from the surgical site. Thus, theinner tube serves as the conduit through which the irrigation fluid anddebris are removed from the surgical site.

[0005] A powered handpiece intended for use with the above cuttingattachments is designed with complementary features that facilitate thedrawing of the suction away from the surgical site. Specifically, thistype of handpiece is provided with a suction bore to which a suctionpump is applied. The coupling assembly allows fluid flow from the insideof the rotating tube to the suction bore. Moreover, the handpiece isprovided with a valve for regulating fluid flow through the suctionvalve. Thus, a surgeon using this type of handpiece can, with one hand,both manipulate the cutting accessory and regulate the rate at whichfluid is drawn from the surgical site.

[0006] While current handpieces have provided useful for both drivingcutting attachments and drawing a suction, there are some disadvantagesassociated with their use. In particular, current handpieces and theircomplementary cutting attachments are designed so that irrigation fluidis introduced into the annular channel through a supply line that isseparate from the handpiece. While this supply line may be attached to ahandpiece, it has a free end that is typically located forward of thehandpiece coupling assembly. The free end of this line has to bemanually fitted to an inlet luer integral with the static sleeve. When,during a surgical procedure, the doctor wants to switch cuttingattachments, this line must first be removed from the cutting attachmentbeing separated from the handpiece. Then, after the new cuttingattachment is installed, the supply line must be manually fitted to thenew attachment. The time it takes to perform these steps adds to theoverall time it takes to perform the surgical procedure.

[0007] Moreover, in these surgical handpieces, the motor is in closephysical proximity to the path through which the suction fluid flowsthrough the handpiece. Accordingly, these handpieces must be constructedto include sufficient seals that prevent liquid flow into the componentsforming the motor. However, over time, and owing to the presence of themoving parts against which these seals press, these seals can wear out.Consequently, it is not uncommon for fluid to enter the motor and causethe components forming the motor to corrode and/or malfunction. Once theintegrity of these seals diminishes, this corrosion and motor componentwear can occur at a relatively fast rate because the fluid drawn throughthe handpiece suction is saline.

[0008] Also, occasionally, debris can clog the cutting accessoryrotating tube through which the suction is drawn from the surgical site.This clogging is especially prone to occur in cutting accessoriesdesigned for performing sinus surgery. This is because the diameter ofthe bore through which this suction flow travels is relatively narrow.Presently, there are two ways a surgeon can try to remove this type ofclog in order to reestablish suction at the surgical site. One methodinvolves introducing a large quantity of irrigation fluid into thesurgical site. The surgeon takes this action by momentarily running theirrigation pump used to supply fluid at a high speed/high flow flushsetting. The introduction of this large quantity of water causes a largefluid pressure head to develop in the rotating tube upstream of theclog. If the conditions are right, the pressure head of this fluidforces the clog-causing debris to flow downstream out of the rotatingtube. One problem with this clog removal technique is that the switchesfor regulating the irrigation pump are typically located off thehandpiece. In order for the surgeon to be able to control the pump,he/she must actuate a separate foot or hand switch or instruct anassistant to perform this operation. In each of these situations, thesurgeon may have to significantly divert his/her attention from theactual surgical procedure being performed. Still another problem withthis method of clog removal is that, often, it simply does not work.Then, the surgeon is left with a situation in which excess fluid hasbeen introduced into the patient.

[0009] The second method of clog removal is more mechanical. This methodinvolves running a rigid wire down the rotating tube in order to forcethe clog out of the tube. When a surgeon has to take this action, he/shemust first withdraw the cutting attachment from the surgical site. Then,once the clog is removed, the cutting attachment must be repositioned sothat the surgical procedure can be completed. The need to perform thesetasks adds to the overall time it takes to perform the surgicalprocedure.

SUMMARY OF THE INVENTION

[0010] This invention relates to an improved powered surgical handpieceand a cutting accessory for use with the handpiece. This inventionincludes a motor that has a rotor integral with the cutting accessoryand complementary windings that are integral with the handpiece. Thehandpiece has a coupling assembly for holding the cutting attachment tothe handpiece that has a conduit through which irrigation fluid isintroduced into the attachment for application to the surgical site. Thehandpiece of this invention also has a valve for regulating fluid flowthrough the conduit through which a suction is normally drawn. Dependingon the setting of this valve, a suction can be drawn through the cuttingattachment, the suction shut off or irrigation fluid can be introducedinto the suction conduit in order to flush out any debris lodged in theconduit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention is pointed out with particularity in the claims.The above and further features of this invention may be betterunderstood by reference to the following description taken inconjunction with the accompanying drawings in which:

[0012]FIG. 1 is a perspective view of a powered surgical handpiece ofthis invention and a complementary cutting accessory attached to thehandpiece;

[0013]FIG. 2 is a cross sectional view of the distal end of thehandpiece as well as of the portion of the cutting accessory seated inthe handpiece;

[0014]FIG. 2A is a detailed cross sectional view of the motor depictedin FIG. 2;

[0015]FIG. 3 is a perspective view of the cutting accessory;

[0016]FIG. 4 is a cross sectional view of the cutting accessory;

[0017]FIG. 5 is a enlarged view of the distal end of the handpiece;

[0018]FIG. 6 is a section view of a lateral slice of the handpiece takenalong line 6-6 of FIG. 5;

[0019]FIG. 7 is a cross sectional view of the inside of the handpiece;

[0020]FIG. 8 is a perspective cutaway view of the handpiece;

[0021]FIG. 9 is a section view of a lateral slice of the handpiece takenalong line 9-9 of FIG. 7;

[0022]FIG. 10 is a cross sectional view of the inside of the handpiecedepicting the fluid conduits in the end cap that lead to and from thevalve member;

[0023]FIG. 11 is a perspective view depicting the relationship of theslide lever, the slide rod and valve member;

[0024]FIG. 12 is a plan view of the relative position of the valvemember and the associated conduits with the valve member is in thesuction full on state;

[0025]FIG. 13 is a plan view of the relative position of the valvemember and the associated conduits when the valve member is in thesuction partial on state;

[0026]FIG. 14 is a plan view of the relative position of the valvemember and the associated conduits when the valve member is in thesuction-and-purge off state; FIG. 15 is a plan view of the relativeposition of the valve member and the associated conduits when the valvemember is in the purge flow on state; and

[0027]FIG. 16 is a block diagram of how an alternative cutting accessoryis coupled to an alternative shaft of an alternative handpiece of thisinvention.

DETAILED DESCRIPTION

[0028]FIGS. 1 and 2 depict a powered surgical handpiece 20 of thisinvention along with a cutting accessory 22 that is driven by thehandpiece. The handpiece 20 has a generally cylindrical sleeve-likeshell 24 that serves as the housing for the other components of thehandpiece. The proximal end of the cutting accessory 22 is also seatedin shell 24. (Hereinafter “front”, “forward” and “distal” shall beunderstood to means portions of the handpiece 20 or cutting accessory 22located towards the end of the cutting accessory applied to the surgicalsite. “Rear”, “rearward” and “proximal” shall be understood to beportions of the handpiece 20 and cutting accessory 22 located away fromthe end of the cutting accessory applied to the surgical site.)Collectively, the handpiece 20 and cutting accessory 22 are providedwith components that form a motor 26 for actuating the cutting accessory22. The energization signals that are applied to the motor 26 aregenerated by a control console 28 and applied to the motor over a powercable 30. One such control console 28 that can be employed to generatethe energization signals is the TPS™ control console manufactured by theApplicant's Assignee. A switch assembly, such as a foot switch, notillustrated and not part of this invention, is used for regulating theactuation of the handpiece motor 26. This switch assembly is connectedto the control console 28. Based on the signals generated by the switchassembly, the control console 28 applies the energization signals to thehandpiece motor 26.

[0029] The handpiece 20 includes a coupling assembly 32 that releasablyholds the cutting accessory 22 to the handpiece. An irrigation pump 34applies an irrigation fluid to a supply line 36 that is fitted in shell24. The irrigation fluid is introduced into the cutting accessory 22 forapplication to the surgical site through the coupling assembly 32. Inthe preferred version of the invention, irrigation pump 34 is a modulebuilt into and regulated by the control console 28.

[0030] A suction is drawn from the surgical site through the cuttingaccessory 22 and handpiece 20 by a suction pump 38. A manually-set slidelever 40 extends around the outside of the shell 24 and is locatedimmediately rearward of the coupling assembly 32. Slide lever 40 setsthe position of a valve member 42 internal to the handpiece 20 whichregulates fluid flow through a suction conduit integral with the cuttingaccessory 22. Depending on the position of the valve member 42, suctionpump 38 may draw a suction through the conduit, the suction flow may beattenuated, the suction flow may be completely shut off or the flow fromirrigation pump 34 may be directed through the cutting accessory suctionconduit.

[0031] The cutting accessory 22, now described by reference to FIGS. 3and 4, includes a static hub 46 formed of plastic such as apolycarbonate plastic. Static hub 46 has a proximal end 48 with acircular cross sectional profile. The static hub 46 has a distal end 49formed integrally with the proximal end 48, that has a cross sectionalprofile that is at least partially asymmetric relative to thelongitudinal axis of the hub. In the depicted version of the invention,this static hub distal end 49 is formed so that one surface thereof hasa round profile and the opposed surface is shaped to define an alignmentkey 50. The alignment key 50 projects beyond the circle defined by theproximal end 48 of the hub 46 and is shaped to have a flat outersurface. A through bore 47 extends axially through static hub 46 fromthe proximal end 48 to the distal end 49.

[0032] The static hub 46 is further formed to have a rectangular notch52 that extends inwardly from the flat surface of the alignment key 50.As discussed hereinafter, a complementary component of the handpiececoupling assembly 32 seats in notch 52 to hold the cutting accessory 22to the handpiece 20. A fluid inlet bore 54 extends perpendicularlyrelative to the longitudinal axis of accessory 22 from the alignment key50 to through bore 47. Fluid inlet bore 54 serves as the conduit throughwhich irrigation fluid is introduced into the cutting accessory 22 fromsupply line 36. In the depicted version of the invention, an irrigationseal 56 formed from a soft rubber such as is sold under the trademarkVITON by the duPont Company of Delaware is seated around the open end offluid inlet bore 54. Irrigation seal 56 is seated in a cutaway space 58integral with notch 52. Seal 56 is shaped so that the outer surfacethereof is flush with the outer flat surface of the alignment key 50.

[0033] A rigid, outer tube 60 formed of stainless steel is firmlyconnected to the static hub 46 and extends forward from the distal endof the through bore 47. In the depicted version of the invention, theouter tube 60 is shown as having a closed distal end though that not mayalways be the case. (The distal end of the outer tube 60 is the end ofthe tube applied to the surgical site.) Outer tube 60 is formed to havea fluid inlet opening 62 that is concentric with and has the same radiusas fluid inlet bore 54.

[0034] Cutting accessory 22 also has a rotating hub 63 that is locatedrearward of static hub 46. Rotating hub 63 is formed from a plastic suchas polycarbonate plastic. The rotating hub 63 has a main body 66 that islocated immediately rearward of proximal end 48 of static hub 46. In thedepicted version of the invention, the cross sectional profile ofrotating hub 63 is identical to that of the adjacent static hub proximalend 48.

[0035] The rotating hub 63 is formed to have a neck 68 and a head 70that extend forward from the main body 66 into the static hub proximalend 48. More specifically, neck 68 extends forward from body 66 and hasa constant diameter cross section profile less than the diameter of themain body. Head 70 is shaped to have a tapered profile such that theportion of the head immediately adjacent neck 68 has a diameter greaterthan that of the neck and the most distal end of the head has across-section diameter approximately equal to the diameter of the neck.The neck 68 and head 70 are seated in complementary shaped bores 72 and74, respectively, formed in the static hub proximal end 48. Bores 72 and74, it will be observed, surround and are contiguous with through bore47. More specifically, the hubs 46 and hub 63 are formed so that thereis an interstitial gap between the outer surfaces of neck 68 and head 70and the inner surfaces of the static hub 46 that define bores 72 and 74.In preferred versions of the invention, this annular gap, notidentified, is between 20 and 25 mils (0.5 and 0.7 mm). This gap reducesfriction between the interface of the neck 68 and head 70 and the statichub 46.

[0036] Rotating hub 63 is further formed with an axially extendingthrough bore 76 that is concentric with the static hub through bore 47.An outwardly tapered counterbore 78 is formed with through bore 76 atthe proximal end of the rotating hub 63.

[0037] A rotating inner tube 79 is securely mounted to the inner wallthat defines through bore 76 in order to turn in unison with rotatinghub 63. Inner tube 79 extends forward from the distal end of rotatinghub 63 into the center of outer tube 60. The distal end of inner tube 79is formed to serve as a cutting head. In the depicted versions of theinvention, the distal end of the inner tube 79 is open and has sharpedges so that this end of the tube functions as a planar. It should, ofcourse, be recognized that different heads may be attached to the distalend of the inner tube so that the cutting accessory 22 may serve as aburr, a shaver, a resector or other cutting device.

[0038] It should be realized that when the cutting accessory 22 is acutter or a shaver, the distal end of the static outer tube 60 isclosed. In these cutting accessories 22, the distal end of the innertube 79 is dimensioned to abut against the inner wall of the closeddistal end of the outer tube 60. Thus, the inner tube 79 holds the mainbody 66 and head of the rotating hub 63 away from, respectively, thedistal end of the static hub 46 and the inner wall of the static hubthat defines bore 74. This holding off of the rotating hub 63 from theadjacent surfaces of the static hub 46 as well as the fact that neck 68is spaced inwardly from the walls defining bore 72 serves tosubstantially eliminate frictional between the hubs.

[0039] Outer and inner tubes 60 and 79, respectively, are furtherdimensioned so that there is a small annular channel 81 between theouter wall of the inner tube 79 and the adjacent inner wall of the outertube 60. Annular channel 81 serves as the conduit through whichirrigation fluid flows from the fluid inlet bore 54 and the fluid inletopening 62 to the surgical site. The hollow center of inner tube 79serves as a conduit 82 through which a suction is applied to thesurgical site for drawing fluid and debris away from the site.

[0040] The handpiece 20 is now described in detail with an initialdiscussion of the construction of the coupling assembly 32, best seen byreference to FIGS. 2, 5 and 6. The front end of the handpiece 20 isprovided with a solid coupling body 86 formed of PEEK plastic that isseated in the front end of shell 24. More specifically, in the depictedversion of the invention, the forward end of shell 24, is shaped tosubtend an arc of approximately 200 to 260°. Immediately rearward ofthis section of the shell 24, the shell is shaped to have aforward-directed front plate 83.

[0041] The section of coupling body 86 seated in shell 24 thus has anexposed outer surface 85. The coupling body 86 is further shaped to havea head section 87 that extends forward of shell 24. Head section 87 hasa cross-sectional profile that is approximately equal to that of theadjacent end of the shell 24 from which the head extends. Coupling body86 has an axially extending bore 88 dimensioned to receive static hub46. The coupling body 86 is formed so that bore 88 has a distal opening90 with a cross-sectional profile identical to that of the static hubdistal end 49, including the alignment key 50. This configurationinsures that the static hub 46 seats in coupling body 86 in a specificorientation for purposes to be explained below.

[0042] The coupling assembly 32 also includes an oval-shaped coupler arm92. The arm 92 is slidably mounted to the outside of coupler body 86 soas to move perpendicularly relative to the longitudinal axis of thehandpiece 20. Coupler arm 92 has two parallel, spaced apart links 94each of which is seated in a separate slot 96 formed by an interstitialspace between the distal end of the shell 24 and the proximal end of thecoupler body head section 87. Links 94 are connected together at one endby a locking member 98. The locking member 98 is positioned adjacent anopening 102 in the exposed surface 85 of the coupler body 86 rearward ofhead section 87. Opening 102 extends into the distal section 90 of bore88. The locking member 98 is formed to have a tab 104 that extendsthrough opening 102 into bore 88. Tab 104 is the component of thecoupling assembly 32 that seats in notch 52 to hold the cuttingaccessory 22 to the handpiece 20. The tab 104 is formed with a forwardfacing surface 105 that is angled rearwardly to facilitate the fittingof the cutting accessory 22 to the handpiece 20.

[0043] Irrigation fluid is introduced into the cutting accessory 22through the coupler arm 92. Specifically, the distal end of the supplyline, distal supply line 36 a in the drawings, is fitted into a rearwardfacing bore 106 formed in locking member 98. Locking member 98 has acylindrical outlet fitting 108 that is in fluid communication with bore106 and is directed inwardly towards the longitudinal axis of thehandpiece 20. Outlet fitting 108, which is located rearward of tab 104,is positioned so that when the tab 104 seats in the cutting accessorynotch 52, the fitting 108 seats in the opening integral with irrigationseal 56. Thus, when the cutting accessory 22 is mounted to the handpiece20, fluid flows from the supply lines 36 and 36 a, through bore 106 andfitting 108, into accessory inlet bore 54, inlet opening 62 and channel81 to the surgical site.

[0044] The ends of links 94 distal from locking member 98 are connectedtogether by a semi-circular web 110. Two springs 112 bias coupler arm 92so that tab 104 is normally urged into bore 88. The springs 112, whichare parallel to each other, are connected at one end to separate posts114 fitted in coupler body head section 87. The opposed end of eachspring 112 is connected to a small set screw 116 that extends forwardfrom an adjacent one of the links 94. The coupler body head section 87is further formed to have opposed grooves 118 in which each spring 112is seated. Since the springs 112 are seated in grooves 118, thelikelihood of an individual inadvertently disturbing a spring or fingeror an article of clothing becoming caught in one of the springs issubstantially eliminated.

[0045] The motor 26 seen best in FIGS. 2 and 2A, includes a stator 122that is mounted in the shell 24 and a set of magnets 124 that aredisposed in the cutting accessory rotating hub 63 as seen in FIGS. 2, 4and 7. In one preferred version of the invention, the motor is afour-pole, three-phase brushless, sensorless DC motor. Morespecifically, the stator 122 includes a set of three windings 121 thatare wound around a cage 123. Electrically, the windings are 120° apartfrom each other. It should be understood that physically, the windingsmay overlap. The stator 122 is encased in an insulating shell 125 thatis formed from non-conductive material such as PEEK plastic. Shell 125is shaped so as to define an axially extending center space 126 in whichthe cutting accessory rotating hub 63 is seated. More particularly, theshell 125 is dimensioned so that there is a small air gap between theinner wall of the shell defining space 126 and the outer wall of therotating hub 63. This air gap is approximately 20 mils, (0.5 mm). Thisair gap essentially eliminates the rotating friction between therotating hub 63 and the shell 125.

[0046] The rear end of stator shell 125 is seated on an annular step 128formed integrally with handpiece shell 24. Step 128 extends inwardlyfrom the inner wall of handpiece shell 24 towards the longitudinalcenter of the handpiece 20.

[0047] Since motor 26 is a four-pole motor, four magnets 124 are mountedin the rotating hub. The magnets 124 are elongated members that arespaced equiangularly around the longitudinal axis of the cuttingaccessory 22. The magnets are formed so that their N/S polar orientationis located along an axis perpendicular to the longitudinal axis of thecutting accessory 22. Thus, for a first one of the magnets 124, theNorth pole is oriented towards the center of the rotating hub. Themagnets 124 adjacent the first magnet are arranged so that their Southpoles are oriented towards the center of the rotating hub.

[0048] The magnets 124 may have a cross sectional profile that is eithercurved or squared. Alternatively, the magnets may even have arcuatecross sectional profile. In these versions of the magnets 124, the outerface of each magnet may have a convex profile having a first radiuswhile the inner face of the magnet has a concave profile with a radiusless than that of the first radius. The magnets 124 may be made out ofany appropriate material such as samarium cobalt.

[0049] A plunger 134 is seated in the rearward portion of stator 122.The plunger 134 is formed from stainless steel. The plunger 134 has acylindrical stem 136. Stem 136 is mounted in a plunger bearing assembly138. The plunger bearing assembly 138 is seated in the front end of thevalve member 42 as will be described hereinafter. Plunger 134 is furtherformed with a head 140 that is formed integrally with and has a largercross sectional diameter than the stem 136. In the depicted version ofthe invention, plunger head 140 is dimensioned so that it comes closeto, but does not abut the adjacent inner wall of the stator 122. Theplunger head 140 has a center section 142 that extends forward from theouter perimeter of the head. The center section 142 of the plunger head140 seats in counterbore 78 formed in the proximal end of rotating hub63.

[0050] A bore 146 extends axially through plunger 134 from the proximalend of the plunger to the distal end. Bore 146 serves as a conduitthrough which fluid flows between valve member 42 and rotating hub bore76. In the depicted version of the invention, the plunger head 140 has acounterbore 148, concentric with bore 146, that has the same diameter asthe rotating hub bore 76.

[0051] A coil spring 150 is disposed around plunger stem 136 and extendsbetween plunger bearing 138 and the rearward facing surface of plungerhead 140. Spring 150 provides the biasing force that urges the plunger134 forward so that the plunger imparts a like force to cuttingaccessory 22. A retaining ring 152 fitted in a groove extending aroundthe end of stem 136 seated within the valve member 42 (groove notidentified). Retaining ring 152 abuts against the rearward facingsurface of plunger bearing assembly 138 to prevent the plunger 134 fromseparating from the bearing assembly 138.

[0052] An explanation of how fluid is selectively introduced into anddrawn from conduit 82 of cutting accessory 22 through the handpiece 20of this invention is now set forth with initial reference to FIGS. 7-9.As seen in these drawings, a solid, cylindrical end cap 156 formed ofPEEK plastic is seated in the proximal end of shell 24. End cap 156 isformed with a suction bore 158 that extends laterally through the endcap. It will be observed that suction bore 158 is laterally offset fromthe longitudinal axis of the end cap 156. Suction bore 158 is formed tohave a threaded counterbore 160 which is located at the proximal end ofthe end cap 156. A luer fitting 162 is seated in suction borecounterbore 160. The luer fitting 162 serves as a means to connect asuction line 164 between the suction bore 158 and suction pump 38. Theopposed end of suction bore 158 defines an opening 165 in the distal endface of end cap 156.

[0053] End cap 156 is also formed to have a supplemental conduit 166.The supplemental conduit 166 serves as the conduit in which theelectrical conductors integral with the handpiece 20 are seated(conductors not illustrated). The supplemental conduit 166 extendsforward from the proximal end of the end cap 156. In the depictedversion of the invention, end cap 156 is formed so that supplementalconduit 166 is laterally offset from the longitudinal axis of thehandpiece 20. Supplemental conduit 166 has two sections. There is aproximal section 168 in which the conduit is essentially parallel to thesuction 158. There is also a distal section 170 that is contiguous withand extends forward from proximal section 168. Distal section 170 anglesaway from proximal section 168 and opens in the side of the end cap 156at a point rearward of the distal end of the end cap. The conductorsextend out of the end of the opening of supplemental conduit distalsection 170 and seat in a groove 171 formed on the inner wall of shell24

[0054] (FIG. 9). The conductors extend from the shell 24 to the stator122 to provide energization signals to motor 26. A tube-shaped ferule169 extends rearwardly from the open proximal end of the supplementalconduit 166. Ferule 169 protects the end of the cable 30 that extendsinto the conduit 166.

[0055] The irrigation fluid supply line 36 is fitted in a groove 172that extends longitudinally along the outside of shell 24 seen best byreference to FIGS. 2, 5 and 10. Supply line 36 terminates at one end ofa T-connector 174 mounted to the end cap. Distal supply line 36 aextends from the opposed end of T-connector 174 into the bore 106associated with coupler arm 92. More specifically, groove 172 extendsforward a short distance from T-connector 174 and distal supply line 36a is seated in the groove. Distal supply line 36 a extends throughgroove 172 and out through an opening 175 in the shell front plate 83.The forward end of the distal supply line 36 a is the end of the linefitted to coupling arm bore 106.

[0056] Focusing on FIG. 10, it can be seen that the center stem ofT-connector 174 is mounted in an L-shaped irrigation bore 176 formed inthe distal end of end cap 156. Bore 176 has an opening 178 in the distalend face of the end cap 156.

[0057] Valve member 42, now described by reference to FIGS. 7 and 11, isshaped to have a generally cylindrical shape. The valve member 42 has acircular, disc-like base 180 that abuts the distal end face of end cap156. The space forward of end cap 156 is the valve chamber 179 ofhandpiece 20. Valve member base 180 has a tear-dropped shaped opening182 that, depending on the position of the valve member 42, isselectively positioned to be in registration with suction bore opening165 or irrigation bore opening 178. The valve member 42 is furtherformed to have tube-like body 184 that extends forward from the distalend of base 180. The body 184 is the portion of the valve member 42 towhich plunger bearing assembly 138 is mated and in which the plungerstem 136 extends. More specifically, the inner wall of valve member body184 is formed to define an annular step 186 in which the plunger bearingassembly 138 is seated.

[0058] The setting of valve member 42 is controlled by slide lever 40.The slide lever 40 has a curved section 190 that fits around the portionof shell 24 that surrounds coupler body 86. Slide lever 40 also has aflat section 192 integral with the curved section 190 that is locatedagainst the exposed surface 85 of the coupler body below coupler arm 92.A slide rod 194 extends rearwardly from slide lever flat section 192.Slide rod 194 is seated in a longitudinally extending groove 196 formedon the inside wall of shell 24. In order to ensure that the slide rodseats in groove 196, the rod is formed to have a semi-circular crosssectional profile.

[0059] Slide rod 194 is provided with a pin 198 (shown in phantom) thatextends inwardly towards the longitudinal axis of the handpiece 20. Pin198 seats in a helical groove 202 (shown in phantom) formed in the outersurface of valve member body 184. Thus, the forward/rearwarddisplacement of slide lever 40 and slide rod 194 controls the rotationalposition of valve member 42.

[0060] An extension rod 204, seen in FIGS. 8 and 9, is attached to theproximal end of slide rod 194 to move with the slide rod. Extension rod204 has a generally circular cross sectional profile. The outer half ofextension rod 204 seats in shell groove 196. The inner half of extensionrod 204 seats in a groove 206 formed along the outer wall of end cap156. A small magnet 208 is mounted in an opening in extension rodlocated adjacent the distal end of the rod 204 (opening not identified).

[0061] Extension rod 204 is shaped to have a reduced diameter pin 210that extends rearwardly from the proximal end of the rod 204. Pin 210seats in a forward-facing bore 220 (shown in phantom) formed in theproximal end of end cap 156. A spring 212 extends around pin 210. Spring212 provides a biasing force that push extension rod 204, slide rod 194and slide valve 40 forward. Thus, slide valve 40 is normally positionedto be located immediately rearward of locking member 98.

[0062] A reed switch 216, or other sensor, is seated in the end cap 156to monitor the displacement of magnet 208. In the depicted version ofthe invention, reed switch 216 is mounted in a branch channel 218 thatextends laterally away from the proximal section 168 of supplementalconduit 166. The signal across the reed switch is monitored by a circuitinternal to control console 28. The electrical conductors (notillustrated) that extend to reed switch 216 are fitted in conduit 166.Also, in the depicted version of the invention, branch channel extendsto groove 206 though this need not always be the case. The open/closedstate of reed switch 216 is monitored by a controller internal toirrigation pump 34.

[0063] A tube-like handgrip 220 formed of rubber surrounds shell 24. Thehandgrip 220 surrounds the portion of the shell that extends rearwardfrom plate 83.

[0064] The handpiece 20 of this invention is readied for use by thefitting of the cutting accessory 22 to the handpiece. This is performedby inserting the accessory hubs 46 and 63 into the open end of handpiecebore 88. When the static hub alignment key 50 seats in the bore distalopening 90, the flat face of the key abuts against the angled forwardfacing surface 105 of tab 104. Owing to the angle of surface 105, thisaction causes the tab 104 to automatically retract away from bore 88 sothat the cutting accessory 22 can continue to be fitted in place. Oncenotch 52 of static hub 46 comes in registration with tab 104, springs112 urge locking member 98 towards the center axis of the handpiece sothat the tab seats in the notch. The seating of the tab 104 in notch 52locks the cutting accessory 22 in place.

[0065] Simultaneously with the seating of tab 104 in notch 52, outletfitting 108 comes into registration with accessory inlet bore 54. Thus,the locking of the cutting accessory 22 to the handpiece 20 of thisinvention results in the automatic establishment of a path through whichirrigation fluid can flow through supply lines 36 and 36 a into theannular channel 81 of cutting accessory 22. Thus, once the couplingaccessory 22 is fitted to the handpiece 20 additional time need not bespent establishing this fluid connection.

[0066] It should also be understood that when irrigation fluid isintroduced into the inlet bore 54, the fluid does not flow rearwardbeyond the interface of the static hub 46 and rotating hub 63. This isbecause the pressure head of the fluid is not sufficient to force thefluid between the narrow gap between the hubs 46 and 63.

[0067] When it is necessary to remove the cutting accessory 22 from thehandpiece 20, all one needs to do is manually urge coupler arm web 110inwardly towards shell 24. This action causes tab 104 to retract awayfrom cutting accessory notch 52. Simultaneously with the retraction oftab 104, outlet fitting 108 retracts away from bore 54. Once the tab 104is moved away from notch 52, cutting accessory 22 can be manuallyremoved from bore 88. The removal of the cutting accessory 22 isfacilitated by the fact that, once the tab 104 is so retracted, theforce of the plunger spring 150 is fully released. Thus, the spring 150pushes the plunger 136 forward so the plunger causes a like displacementof the cutting accessory 22 out of the forward end of the handpiece 20.

[0068] The cutting accessory 22 is actuated by selectively applyingenergization currents to the windings integral with the stator 122.These currents cause magnetic fields to develop which attract themagnets 124 internal to rotation hub 63. The attraction of the magnets124 to the windings causes rotation of hub 63 as well as inner tube 79integrally attached thereto. Plunger 134, which is pressed againstrotating hub 63, rotates with the hub. An advantage of this arrangementis that in this construction only the single bearing assembly 138 isrequired to insure the free rotation of rotor that is integral with themotor. Moreover, since the windings and magnets 124 are contained intheir own sealed housings, and there are no bearings, it is notnecessary to provide a separate sealed housing for the motor 26. Twoadvantages of this construction are that it eliminates both the cost andweight of having to provide a sealed housing. Still another benefit ofthis feature of the invention is that the motor 26 of this handpiece 20does not have any metal components that are exposed to fluid in theevent a seal wears or breaks. Thus, there is little likelihood that themotor of this invention will malfunction due to corrosion-inducedcomponent failure.

[0069] The handpiece 20 of this invention is further configured toregulate whether or not a suction is drawn through or irrigation fluidis applied to conduit 82 integral with the cutting accessory inner tube79. During normal operation of the handpiece 20, valve member 42 has therotational orientation depicted in FIG. 12. Here, the valve member 42 ispositioned so that the largest diameter section of base opening 182 isin registration with opening 165 integral with suction bore 158. Thus,when the valve member 42 is in this position, the maximum possiblesuction is drawn from the surgical site through inner tube conduit 82,rotating hub bore 76, plunger bore 146 and the suction bore by suctionpump 38. Further, when the valve member 42 is in this position, base 180covers and closes irrigation bore opening 178. The sealing closed ofopening 178 prevents irrigation fluid from being introduced into thecenter of the valve member when the suction is being drawn.

[0070] A surgeon attenuates the suction drawn at the surgical site bymoving slide lever 40 rearward towards handgrip 220. This motion causesa like displacement of slide rod 194. The displacement of slide rod 194causes valve member 42 to rotate first to the position depicted in FIG.13. When the valve member 42 is in this position, the narrow diametersection of valve member base opening 182 is in registration with suctionbore opening 165. Thus, at this time, a reduced volume suction flow isdrawn by the pump 38 from the surgical site through the inner tubeconduit 82 and the valve member 42.

[0071] The surgeon may totally turn off the suction drawn at thesurgical site by simply moving the slide lever 40 rearwardly. The likemovement this induces in the slide rod 194 and pin 198 causes the pin torotate the valve member 42 into the position shown in FIG. 14. When inthis state, the valve member 42 covers the both suction bore opening 165and the irrigation bore opening 178. Thus, at this time, there is nofluid flow in any direction through the inner tube conduit 82 to or fromthe surgical site.

[0072] The handpiece 20 of this invention is configured to direct apurge flow through the inner tube conduit 82 in the event the conduitbecomes clogged. Specifically, if this event occurs, or for anotherreason the surgeon wants a very large fluid flow to be introduced intothe surgical site, the surgeon presses the slide lever 40 so that thelever is in its most rearward position. This displacement of the slidelever 40 and the associated slide rod 194 results in two effects. First,this displacement causes the valve member 42 to rotate into the positiondepicted in FIG. 15 in which the large diameter portion of base opening182 comes into registration with irrigation bore opening 178. Secondly,the magnet 208 that moves with the slide rod 194 moves very close toreed switch 216. This motion causes the reed switch 216 to close so thatthe signal produced by the switch changes state. This signal change isinterpreted by control console 28 as an instruction to boost the rate atwhich fluid is discharged from the irrigation pump 34. Thus, the movingof the slide valve 40 to the purge position resets the valve member 42so that irrigation fluid is directed through inner tube conduit 82 andsets the irrigation pump 34 to force a relatively high pressure flowthrough this conduit. Collectively, this means that when the handpiece20 is in the purge state, a relatively high pressure stream of fluid isdirected through the inner tube conduit 82 towards the surgical site. Inmany situations, this high pressure fluid stream has enough force todislodge the debris that are blocking normal suction flow through theinner tube 79.

[0073] Thus, the handpiece 20 of this invention provides a means forautomatically establishing and breaking an irrigation connection to thecutting accessory 22, has relatively few moving parts and has means toprovide a purge flow to the conduit integral with the cutting accessorythrough which the suction flow is normally drawn.

[0074] It should be understood that the foregoing description isdirected to one specific embodiment of the invention. It will beapparent, however, from the description that alternative constructionsof the invention are possible. For example, not all versions of theinvention may have an outlet fitting for providing a fluidcommunications path to the complementary cutting accessory. Similarly,other versions of the handpiece may not be constructed so that therotating hub of the cutting accessory forms part of the motor or with avalve member that can be used to introduce a purge flow into the suctionconduit integral with the cutting accessory.

[0075] For example, it may be desirable to provide a handpiece andcomplementary cutting attachment of this invention with just thedescribed motor 26. These particular components would thus be designedas tools for conventional surgery in which the handpiece does not alsoprovide irrigation fluid and/or draw suction from the site. Similarly,it may be desirable to provide a handpiece that simply functions as anconduit for supplying irrigation fluid to and/or drawing a suction fromthe surgical site that has the features of this invention. Specifically,it will be noted that the setting of valve 42 does not effect the alwaysopen fluid connection between supply lines 36 and 36 a. So when valve 42is in the purge position, there is also fluid flow to the surgical sitethrough annual channel 81.

[0076] Also, the components from which the handpiece and complementarycutting accessory are formed may have alternative constructions thanwhat has been described. For example, it may be desirable to design thecoupling assembly with multiple fingers that are positioned to movetowards and away from the cutting accessory. In this version of theinvention, the cutting accessory would be formed with recesses in whichthese fingers seat. The seating of the fingers in these recesses holdsthe cutting accessory to the handpiece. In these versions of theinvention, the inlet fitting may be built into one of the fingers.

[0077] It should also be recognized that some versions of the invention,the distal end of the outer tube 60 of the cutting accessory 22 may beopen ended. This may be the case when the inner tube 79 is provided witha burr at its head end. In these versions of the invention, the tubescannot be configured to hold the rotating hub 63 off away from thestatic hub 46. Accordingly, in these versions of the invention, a flatring formed of a low friction plastic such as the plastic sold under thetrademark TEFLON by the duPont Company, may be fitted around the forwardend of the rotating tube main body 66. This ring serves as a bearing tominimize the friction between the rotating hub 63 and the static hub 46.

[0078] Alternatively, in some versions of the invention, the distal endof the inlet fitting 108 may seat in a counter bore formed integral withfluid inlet bore 54. An advantage of this version of the invention isthat it may eliminate the need to provide the irrigation seal 56 aroundbore 54.

[0079] Also, alternative versions of the motor may be provided. Forexample, while not optimal, the stator may be embedded in the rotatinghub 63 and the magnets may be mounted to the handpiece. In theseversions of the invention, some type of brushes integral with thehandpiece would provide an electrical path between the control console28 and the windings integral with the stator. Also, in some versions ofthe invention Hall sensors may be mounted in the handpiece 20. Thesesensors would provide signals that indicate the rotational position ofthe rotating hub magnets 124. The control console 28, in turn, uses thesignals representative of the position of these magnets as an input forregulating the energization of the stator windings.

[0080] Moreover, it should likewise be understood that the rotating hub63 may be provided with more or less magnets 124 than has beendescribed. Typically, the rotating hub 63 will be provided with an evennumber of magnets. Similarly, stator 122 may have other constructionsthan what has been described.

[0081] It should likewise be appreciated that there may be versions ofthe invention in which no part of the motor is built into the cuttingaccessory 22. In these versions of the invention, as seen in FIG. 16,the rotating hub 63 a may be provided with notches 212 or other meansfor engaging a complementary coupling member 214 that is integral withthe shaft 216 of the motor 218 built into the handpiece 20 a. In theseversions of the invention, once the rotating hub engages with the shaft,the hub, as well as inner tube 79 rotate in unison with the shaft.

[0082] Also, it should be clear that the structure of the valve membermay very from what has been described. Clearly, the valve member canrotate along an axis different than the longitudinal axis that runsthrough the handpiece 20. It should be clear that, in these versions ofthe invention the conduits in the end cap 156 will have differentorientations than what has been described. Furthermore, there is norequirement that in all versions of the invention in which the handpiece20 is capable of directing a purge flow through the suction conduit ofthe cutting accessory 22 that the handpiece also have a switch assemblyfor controlling the rate of the purge flow. Similarly, in other versionsof the invention, by appropriately designing the components, it may bepossible to provide one of two purge flows to the suction conduit; afirst low-pressure flow and a second high-pressure flow. Thisarrangement may be possible by constructing the handpiece so that onlyafter irrigation bore opening 178 is placed in full registration withthe valve member opening 182 does the reed switch, upon furtheractuation of the slide lever 40, close.

[0083] Moreover, in other versions of the invention, a switch assemblyfor regulating the energization of the suction pump 38 may be built intothe handpiece. This switch assembly may include a second reed switchthat is actuated by magnet 208 or a second magnet that is displaced bythe actuation of slide lever 40. Depending on the open/closed state ofthis reed switch, the control console 28 may either increase or decreasethe suction drawn by pump 38.

[0084] Therefore, it is an object of the appended claims to cover allsuch modifications as come within the true spirit and scope of thisinvention.

What is claimed is:
 1. A cutting accessory for a surgical handpiece,said accessory comprising: a static hub having opposed first and secondends, a through bore that extends axially through said static hub fromthe first end to the second end and means for receiving a lockingelement that holds said static hub in position; a rotating hub formed ofnonmagnetic material that is positioned adjacent the first end of saidstatic hub; at least two magnets disposed in said rotating hub so thatwhen electromotive forces are developed in vicinity of said magnet, saidmagnet rotates so as to cause a like rotation of said rotating hub; andan elongated inner tube that is integrally affixed to said rotating hubso as to rotate in unison with said rotating hub, said inner tubepositioned to extend from said rotating hub and through the through borein said static hub and having an end distal from said rotating hub witha cutting member.
 2. The cutting accessory of claim 1, wherein saidrotating hub is coupled to said static hub.
 3. The cutting accessory ofclaim 2, wherein: said static hub is formed with a first receiving boreadjacent the first end of said hub and a second receiving borecontiguous with the first receiving bore that is spaced from the firstend of said hub, wherein the first and second receiving bores arecontiguous with and surround the through bore and the second receivingbore has a diameter that is greater than the diameter of the firstreceiving bore; and said rotating hub is formed with: a body positionedto be located adjacent the first end of said static hub, said bodyhaving a diameter; a neck that is integrally connected to said body,said neck having a diameter less than the diameter of said body, saidneck positioned to extend forward of said body into the first receivingbore of said static hub; and a head integrally connected to said neck,said head having a diameter greater than the diameter of said neck andbeing positioned to extend forward of said neck so as to be seated inthe second receiving bore of said static hub.
 4. The cutting accessoryof claim 1, further including an outer tube mounted to said static hubthat is positioned to extend over said inner tube.
 5. The cuttingaccessory of claim 4, wherein: said inner tube has an outer wall andsaid outer tube has an inner wall and said inner tube and said outertube are dimensioned so that the outer wall of said inner tube isinwardly spaced from the inner wall of said outer tube so as to definean annular conduit between said tubes; and said static hub is formedwith an inlet bore that is in fluid communication with the annularconduit between said tubes.
 6. The cutting accessory of claim 1 whereinsaid outer tube is shaped to have an asymmetric cross sectional profile.7. A surgical cutting accessory for attachment to handpiece, saidcutting accessory including: a static hub, said static hub shaped tohave: an outer surface; axially opposed first and second opposed ends; athrough bore that extends from the first end to the second end; meansfor receiving a locking element that holds said static hub in position;and an inlet bore that extends inwardly from the outer surface of saidstatic hub to the through bore; an outer tube mounted to said static hubthat extends outwardly from the second end of said static hub over thethrough bore of said static hub; a rotating hub that is located adjacentthe first end of said static hub, said rotating hub having means forcausing rotation of said rotating hub; and an inner tube having aproximal end that is attached to said rotating hub so that said innertube rotates in unison with said rotating hub and a distal end spacedfrom the proximal end, said inner tube positioned to extend forward ofsaid rotating hub through the through bore of said static hub and intosaid outer tube wherein, said inner tube and said outer tube are spacedapart from each other so as to form an annular channel therebetween, theinlet bore of said static hub being in fluid communication with theannular channel, and the distal end of said inner tube is provided witha cutting head.
 8. The cutting accessory of claim 7, further including aseal mounted to said static hub around the said inlet bore, wherein saidseal is positioned to have an outer surface that is flush with the outersurface of said static hub.
 9. The cutting accessory of claim 7, whereinsaid static hub is formed to have an asymmetric cross sectional profile.10. The cutting accessory of claim 9, wherein said static hub is formedto have two outer surfaces, a first one of said outer surfaces having acurved shape and a second one of said outer surfaces having a planarshape and extending between the first outer surface, and said inlet boreextends inwardly from the second outer surface.
 11. The cuttingaccessory of claim 7, wherein said means for rotating said rotating hubincludes at least two magnets disposed in said rotating hub for rotatingsaid hub in response to the generation of local electromagnetic forcefields.
 12. A surgical handpiece for actuating a cutting accessory, saidhandpiece having: a body, said body having a bore that opens from an endof said handpiece for receiving the cutting accessory; a couplingassembly attached to said body for releasably securing the cuttingaccessory in said body; and a stator having windings that is mounted insaid body and shaped so as to define the bore in which the cuttingaccessory is seated.
 13. The surgical handpiece of claim 12 wherein saidbody further includes a bore through which a suction is drawn from thecutting accessory.
 14. A powered surgical tool assembly comprising: acutting accessory, said cutting accessory including: a rotating hub,said rotating hub being formed from non-magnetic material and having atleast two magnets therein; and a cutting device that is integrallymounted to said rotating hub so as to extend forward from said rotatinghub; and a handpiece, said handpiece including: a body, said body havinga bore that opens from an end of said body, wherein said rotating hub isrotatingly disposed in the bore and said cutting device extends out ofthe bore and away from the handpiece body; a coupling assembly mountedto said body for releasably holding said rotating hub in said bore; anda stator disposed in said body, said stator being shaped to define thebore so that said stator surrounds said rotating hub, wherein saidstator is provided with at least one winding so that the application ofenergization current to the at least one winding results in thedevelopment of an electromagnetic field that causes the rotation of saidat least two magnets, said rotating hub and said cutting device.
 15. Thepowered surgical tool assembly of claim 14, wherein: said cuttingaccessory further includes a static hub that is located over saidrotating hub, said static hub being formed to have a through bore andsaid static hub is positioned in an open end of the bore in saidhandpiece body; said cutting device extends through the through bore insaid static hub; and said handpiece coupling assembly engages saidstatic hub so as to hold said static hub and said rotating hub in thebore in said handpiece body.
 16. The powered surgical tool assembly ofclaim 14, wherein: said cutting device is provided with a conduit thatextends from an open end of said cutting device that is distal from saidrotating hub to said rotating hub; and said handpiece body is formedwith a suction bore that is positioned to be in fluid communication withthe conduit of said cutting device so that a suction can be drawn fromthe cutting device conduit through the suction bore of said handpiece.17. A powered surgical handpiece for actuating a cutting attachment, thecutting attachment having a cutting member that is formed with aconduit, said handpiece including: a body, said body being formed with:an attachment bore in which the cutting attachment including one end ofthe cutting member is seated; a suction bore through which a suction isdrawn; and an irrigation conduit through which irrigation fluid isintroduced into said body; a coupling assembly attached to said body forreleasably holding the cutting attachment in the attachment bore; amotor disposed in said body for rotating said cutting attachmentincluding said cutting member; and a valve assembly including: a valvemember positioned in said body for selectively establishing a fluidcommunication path between the conduit of the cutting member and thesuction bore or the irrigation conduit, wherein said valve member ismoveable between a first position in which said valve member establishesa fluid communication path between the conduit of the cutting member andthe suction bore, a second position in which said valve member preventsfluid communication between the conduit of the cutting member and thesuction bore and the irrigation conduit and a third position in whichsaid valve member establishes a fluid communication path between theconduit of the cutting member and the irrigation conduit; and a leverlocated outside of said body that is connected to said valve member formoving said valve member between the first, second and third valvemember positions.
 18. The handpiece of claim 17, further including asensor disposed in said body for monitoring the position of said valvemember and generating a signal when said valve member is moved to thethird valve member position.
 19. The handpiece of claim 17, wherein saidmotor includes: at least two magnets integrally attached to the cuttingaccessory; and a stator disposed in said body for generating anelectromagnet force to cause the rotation of said magnets and thecutting accessory, including the cutting element.
 20. A powered surgicalhandpiece for actuating a cutting accessory, the cutting accessoryhaving a hub and a cutting device that is attached to the hub to movewith actuation of the hub, said handpiece including: a body, said bodyhaving a bore that is open at one end of said body for receiving thecutting accessory hub; a power generating unit mounted in said body thatis connected to said hub for actuating the cutting accessory hub and thecutting device; an irrigation tube attached to said body through whichan irrigation fluid is pumped; and a coupling assembly mounted to saidbody, said coupling assembly having: at least one locking member that ismovably mounted to said body that is positioned to selectively engagethe cutting accessory hub for holding the cutting accessory in saidbody; and an inlet fitting to which said irrigation tube is connected,said inlet fitting being positioned to move with said at least onelocking member so that when said locking member engages the hub, saidinlet fitting is in fluid communication with an inlet bore formed in thecutting accessory hub.
 21. A surgical tool system including: ahandpiece, said handpiece having: a body, said body having a conduitwith a proximal end for receiving irrigating fluid and a distal endthrough which the irrigating fluid is discharged towards a surgicalsite; a valve mounted to said body to regulate fluid flow through theconduit; a sensor mounted to said body to monitor said valve, saidsensor generating a signal representative of valve state; a pumpconnected to the proximal end of the conduit for supplying irrigatingfluid to the conduit; and a control unit connected to said handpiece toreceive the sensor signal and connected to the pump to regulate theoperation of the pump, wherein said control unit is configured toregulate the operation of the pump as a function of the valve state asindicated by the sensor signal.
 22. The surgical tool system of claim21, wherein: said pump is a variable flow rate pump; and said controlunit is connected to said pump to regulate the rate at which said pumpsupplies irrigating fluid as a function of the valve state.
 23. Thesurgical tool system of claim 22, wherein said control unit isconfigured so that, when the sensor signal indicates said valve is in anopen state that maximizes the amount of fluid that can flow to thedistal end of said conduit, said control unit increases the rate atwhich said pump supplies irrigating fluid.
 24. The surgical tool systemof claim 21, wherein: said handpiece further includes a couplingassembly attached to said body for removably attaching an accessory tosaid body; and the distal end of the conduit defines an outlet openingthrough which irrigating fluid is discharged towards an inlet openingintegral with the accessory attached to said body.
 25. The surgical toolsystem of claim 21, wherein: a power producing unit is disposed in saidhandpiece body; said handpiece further includes a coupling assemblyattached to said body for removably attaching an accessory to said bodyand connecting the accessory to said power producing unit; and thedistal end of said conduit is provided with an outlet opening throughwhich irrigating fluid is discharged towards an inlet opening integralwith the accessory attached to said body.
 26. The surgical tool systemof claim 21, wherein: a power producing unit is disposed in saidhandpiece body; and said control unit is connected to said handpiece tosupply an energization signal to said power producing unit.
 27. Thesurgical tool system of claim 26, wherein said power producing unit is amotor.
 28. The surgical tool system of claim 21, wherein the conduit isat least partially formed by a bore that extends at least partiallythrough said handpiece body.
 29. The surgical tool system of claim 21,wherein: said body includes a suction fitting; and said valve isconfigured to selectively connect the distal end of the conduit to theproximal end of the conduit or to said suction fitting.
 30. The surgicaltool system of claim 21, wherein: said body includes a suction fitting;and said valve is configured to selectively: connect the distal end ofthe conduit to the proximal end of the conduit; connect the distal endof the conduit to said suction fitting; or close off the conduit firstbranch from both the proximal end of the conduit and the suctionfitting.
 31. A surgical tool system including: a handpiece, saidhandpiece having: a body, said body having a conduit with a proximal endfor receiving irrigating fluid and first and second branches that extendforward from the proximal end, each branch having an outlet throughwhich irrigating fluid is discharged towards a surgical site; a valvemounted to said body to regulate fluid flow through the conduit firstbranch; a sensor mounted to said body to monitor said valve, said sensorgenerating a signal representative of valve state; a pump connected tothe proximal end of the conduit for supplying irrigating fluid to theconduit; and a control unit connected to said handpiece to receive thesensor signal and connected to the pump to regulate the operation of thepump, wherein said control unit is configured to regulate the operationof the pump as a function of the valve state as indicated by the sensorsignal.
 32. The surgical tool system of claim 31, wherein: said pump isa variable flow rate pump; and said control unit is connected to saidpump to regulate the rate at which said pump supplies irrigating fluidas a function of the valve state.
 33. The surgical tool system of claim31, wherein: said pump is a variable flow rate pump; said control unitis connected to said pump so that, when the sensor signal indicates saidvalve has opened the conduit first branch for fluid flow, said controlunit increases the rate at which said pump supplies irrigating fluid.34. The surgical tool system of claim 31, wherein: said handpiecefurther includes a coupling assembly attached to said body for removablyattaching an accessory to said body; and the distal end of the conduitfirst branch defines an outlet opening through which irrigating fluid isdischarged towards an inlet opening integral with the accessory attachedto said body.
 35. The surgical tool system of claim 31, wherein: saidbody includes a suction fitting; and said valve is configured toselectively connect the conduit first branch to the proximal end of theconduit or to said suction fitting.
 36. The surgical tool system ofclaim 31, wherein: said body includes a suction fitting; and said valveis configured to selectively: connect the conduit first branch to theproximal end of the conduit; connect the conduit first branch to saidsuction fitting; or close off the conduit first branch from both theproximal end of said conduit and the suction fitting.
 37. The surgicaltool system of claim 31, wherein said body does not have any structuralmembers for regulating fluid flow from the conduit proximal end to andthrough the conduit second branch.
 38. The surgical tool system of claim31, wherein: said handpiece further includes a coupling assemblyattached to said body for removably attaching an accessory to said body;and each of the conduit first and second branch outlets are directed tothe accessory attached to said body.
 39. The surgical tool system ofclaim 31, wherein at least a portion of the conduit is formed by a borethat extends through the handpiece body.
 40. A surgical tool system,said system comprising: a handpiece, said handpiece having: a body; acoupling assembly attached to said body for removably attaching anaccessory to said body; a conduit extending through said body, saidconduit having a proximal end for receiving irrigating fluid and adistal end, the distal end of said conduit being positioned in said bodyso that the irrigating fluid discharged through the distal end isdischarged towards an opening in the attached accessory; a valveattached to said body to regulate fluid flow through said conduit; and asensor mounted to said body and configured to generate a sensor signalrepresentative of valve state; a pump connected to said handpiece forsupplying irrigating fluid to the proximal end of said conduit; and acontrol unit connected to said handpiece to receive the sensor signaland connected to said pump to regulate the operation of said pump, saidcontrol unit being configured to regulate the operation of the pumpbased on the sensor signal.
 41. The surgical tool system of claim 40,wherein: said pump is a variable flow rate pump; and said control unitis connected to said pump to regulate the rate at which said pumpsupplies irrigating fluid as a function of the valve state.
 42. Thesurgical tool system of claim 41, wherein said control unit isconfigured so that, when the sensor signal indicates said valve is in anopen state that maximizes the amount of fluid that can flow to thedistal end of said conduit, said control unit increases the rate atwhich said pump supplies irrigating fluid.
 43. The surgical tool systemof claim 40, wherein: a power producing unit is disposed in saidhandpiece body; said coupling assembly is further configured toremovably connect the accessory to said power producing unit; and saidcontrol unit is connected to said handpiece to supply an energizationsignal to said power producing unit.
 44. The surgical tool system ofclaim 43, wherein said power producing unit is a motor.
 45. The surgicaltool system of claim 40, wherein: said body includes a suction fitting;and said valve is configured to selectively: connect the distal end ofsaid conduit to the proximal end of said conduit; or connect the distalend of said conduit to said suction fitting.
 46. The surgical toolsystem of claim 40, wherein: said body includes a suction fitting; andsaid valve is configured to selectively: connect the distal end of saidconduit to the proximal end of said conduit; connect the distal end ofsaid conduit to said suction fitting; or close off the distal end ofsaid conduit from both the proximal end of said conduit and the suctionfitting.
 47. The surgical tool system of claim 40, wherein said conduitis at least partially formed by a bore that extends at least partiallythrough said handpiece body.
 48. A surgical tool system, said systemcomprising: a handpiece, said handpiece having: a body, said body havinga conduit extending through said body, said conduit having a proximalend for receiving irrigating fluid and two branches that extend forwardfrom the proximal end, each branch having a distal end wherein, thedistal ends of the branches being positioned in said body so that theirrigating fluid discharged through the distal ends is discharged towardthe attached accessory; a coupling assembly attached to said body forremovably attaching an accessory to said body wherein, the distal endsof the branches are positioned in said body so that the irrigating fluiddischarged through the distal ends is discharged toward the attachedaccessory; a valve attached to said body to regulate fluid flow througha first one of the conduit branches; and a sensor mounted to said bodyand configured to generate a sensor signal representative of valvestate; a pump connected to said handpiece for supplying irrigating fluidto the proximal end of said conduit; and a control unit connected tosaid handpiece to receive the sensor signal and connected to said pumpto regulate the actuation of said pump, said control unit beingconfigured to regulate the operation of the pump based on the sensorsignal.
 49. The surgical tool system of claim 48, wherein: said pump isa variable flow rate pump; and said control unit is connected to saidpump to regulate the rate at which said pump supplies irrigating fluidas a function of the valve state wherein, when the sensor signalindicates said valve is an open state that allows fluid flow from theproximal end of the conduit to and through the conduit first branch,said control unit increases the rate at which said pump suppliesirrigating fluid.
 50. The surgical tool system of claim 48, wherein: apower producing unit is disposed in said handpiece body; said couplingassembly is further configured to removably connect the accessory tosaid power producing unit; and said control unit is connected to saidhandpiece to supply an energization signal to said power producing unit.51. The surgical tool system of claim 48, wherein: said body includes asuction fitting; and said valve is configured to selectively: connectthe conduit first branch to the proximal end of said conduit; or connectthe conduit first branch to said suction fitting.
 52. The surgical toolsystem of claim 48, wherein: said body includes a suction fitting; andsaid valve is configured to selectively: connect the conduit firstbranch to the proximal end of the conduit; connect the conduit firstbranch to said suction fitting; or close off the conduit first branchfrom both the proximal end of said conduit and the suction fitting. 53.A surgical handpiece comprising: a body; a coupling assembly forremovably attaching an accessory to said body; a conduit integrallyassociated with said body, said conduit having a proximal end forreceiving irrigating fluid and a distal end, the distal end of saidconduit being positioned on said body so that the irrigating fluiddischarged through the distal end is discharged towards the attachedaccessory; a valve attached to said body to regulate fluid flow throughsaid conduit; and a sensor mounted to said body and configured togenerate a sensor signal representative of valve state.
 54. The surgicalhandpiece of claim 53, wherein: a power producing unit is disposed insaid body; and said coupling assembly is further configured toreleasably connect the accessory to said power producing unit.
 55. Thesurgical handpiece of claim 54, wherein said power producing unit is amotor.
 56. The surgical handpiece of claim 53, wherein: said bodyincludes a suction fitting; and said valve is configured to selectivelyconnect the distal end of the conduit to the proximal end of the conduitor to said suction fitting.
 57. The surgical handpiece of claim 53,wherein: said body includes a suction fitting; and said valve isconfigured to selectively: connect the distal end of the conduit to theproximal end of the conduit; connect the distal end of the conduit tosaid suction fitting; or close off the distal end of the conduit fromboth the proximal end of said conduit and the suction fitting.
 58. Thesurgical handpiece of claim 53, wherein said conduit is at leastpartially formed by a bore that extends at least partially through saidhandpiece body.
 59. A surgical handpiece comprising: a body; a couplingassembly for removably attaching an accessory to said body; a conduitintegrally associated with said body, said conduit having a proximal endfor receiving irrigating fluid and two branches that extend forward fromthe proximal end, each branch having a distal end, the distal ends ofthe branches being positioned so that the irrigating fluid dischargedthrough the distal ends is discharged towards the attached accessory; avalve attached to said body to regulate fluid flow through a first oneof the conduit branches; and a sensor mounted to said body andconfigured to generate a sensor signal representative of valve state.60. The surgical handpiece of claim 59, wherein: a power producing unitis disposed in said body; and said coupling assembly is furtherconfigured to releasably connect the accessory to said power producingunit.
 61. The surgical handpiece of claim 60, wherein said powerproducing unit is a motor.
 62. The surgical handpiece of claim 59,wherein: said body includes a suction fitting; and said valve isconfigured to selectively connect the conduit first branch to theproximal end of the conduit or to said suction fitting.
 63. The surgicalhandpiece of claim 59, wherein: said body is formed with a suctionfitting through which a suction is drawn; and said valve is configuredto selectively: connect the conduit first branch to the proximal end ofthe conduit; connect the conduit first branch to said suction fitting;or close off the conduit first branch from both the proximal end of saidconduit and the suction fitting.
 64. The surgical handpiece of claim 59,wherein said conduit is at least partially formed by a bore that extendsat least partially through said handpiece body.
 65. The surgicalhandpiece of claim 59, wherein said body does not have any structuralmembers for regulating fluid flow from the conduit proximal end to andthrough the conduit second branch.